In 20 12, NYSE revised the index fuse mechanism, mainly including the following aspects: First, the Standard & Poor's 500 index was set as the fuse benchmark index instead of the Dow Jones Industrial Average; The second is to modify the fuse threshold to three grades: 7%, 13% and 20%, and the new fuse mechanism will be implemented from February 4, 200013. \ r \ The fuse mechanism, also known as the automatic stop mechanism, refers to the measures taken by the exchange to suspend trading to control risks when the volatility of the stock index reaches the specified fuse point. Specifically, it is a mechanism to set a fuse price for the contract before the contract reaches the price limit, so that the contract trading quotation can only be traded within this price range for a period of time. \ r \ The fuse mechanism of U.S. stocks specifically means that the new york stock market drops by 7% and trading is suspended before 3: 25pm15min; After 3: 25, trading will not be suspended. It fell by 13%. Before 3: 25 pm, the suspension will be suspended again 15 minutes. After 3: 25, trading will not be suspended. Fall 20%, once triggered, immediately close the position. \ r \ For detailed information about the decline of the Dow Jones index, please visit:/ask/84cc771615827750.html? Zd view more content